Despite the directionality in our SEM, the relations between impulsivity and either working memory or reversal learning performance are purely correlational and subsequent waves of our study may help to determine whether development of ECF in general and working memory or reversal learning in particular predict declines in impulsivity. It is possible for example that impulsivity interferes with working memory performance by challenging the system with task irrelevant response tendencies that are difficult to control. This may lead to poorer performance on working memory tasks. It is also possible that impulsivity reduces attention to changes in reward contingencies. If either of these were the case, then developmental changes in impulsivity would predict changes in working memory or reversal learning rather than the other way around.
